Feed-operating mechanism for sewing-machines



(No Model.)

J. TRIPP. FEED OPERATING MECHANISM FOR SEWING MACHINES. No. 409,129. Patented Aug. 13, 1889.

N PETERS. Pholo-Lilhagmphen Walhinglon. ac.

UNITED STATES PATENT OFFICE.

JAMES TRIPP, OF NEIV YORK, N. Y., ASSIGNOR TO GERRIT S. SCOFIELD AND FRANK M. SCOFIELD, BOTH OF GREENWVICH, CONNECTICUT.

FEED-OPERATING MECHANISM FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 409,129, dated August 13, 1889. Application filed )ctober 5,1888. Serial No. 287,283. (No model.)

To all whom it may concern.-

Be it known that I, JAMES TRIPP, of the city, county, and State of New York, have invented certain new and useful I1nprovements in Sewing-Machines, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

The present invention relates to various improvements in the feed mechanism of sewing-machines, which improvements will be carefully explained in the following description and specifically pointed out in the claims to follow the description.

In the drawings, Figure 1 is a plan View of the under side of the bed-plate of a sewingmachine. Fig. 2 is a detail elevation view of the right-hand end of the main shaft, showing the eccentric that actuates the shuttlelevers and the two cams (to be hereinafter more fully described) that actuate the feedbar levers. Fig. 3 is a section of the vertical portion of the bracket-arm that supports the main shaft, this section being taken on plane 00 x of 2 across the main shaft. Fig. 4: is a like section across the main shaft on plane y y-that is, between the eccentric of the shuttle-levers and the cams of the feed-levers. Fig. 5 is a like section of the main shaft on plane 2' 2, but looking from the fly-wheel.

Referring to the views in detail, A inclicates the shuttle-plate or bed-plate of the machine.

13 is the main shaft, and C the vertical portion or standard of the bracket, of usual form, that supports the main shaft.

D is an eccentric on the main shaft, which is embraced by a yoke E on the upper part of the lever F, which lever is pivoted to the standard C at G and at its lower end is connected to the shuttle-lever II in the usual manner. These parts are of the common form, and their operation is well understood.

I is the feed-lever, which is supported on the usual form of adjustable fulcrum J, and is operated by the main shaft, and at its lower end is pivotally connected to one end of the vibrating lever K, which at its other end is connected to the feed-bar L, the mode of connection to such feed-bar being as usually practiced, and the form of the bar being common.

-which it has vertical reciprocation to produce v the vertical motion of the feed-bar. This block is pivotally attached to the shank of the screw-nut J, and this shank extends through a vertical slot in the standard C and is secured at any desired position by its nut.

I will now describe the means for connecting the upper end of the vertical feed-bar lever I to the main shaft. The object in the use of the connections I show is to obviate the undue friction and tendency to bind that. 62(- ist in the well-known forms of such connections-that is to say, since the feed-bar lever has a vertical followed by an angular motion the parts on the main shaft that effect these two motions cannot be positioned alike relatively to the shaft and the lever. The result is that as one such part ceases to act upon the lever and the other part begins its operation there is an irregularapplication of power from the main shaft to the feed-lever, which produces not only a binding with extra friction and wear, but interferes with the smooth running and speed of the machine.

The means I employ for connecting the feed-lever to the main shaft are these: Upon the shaft are two cams M and N. These cams are of proper size and position relatively to give the desired motions to the lever I. O is a fork upon the end of the lever I which embraces the cam M, and P is a link or square yoke that incloses the cam N, which yoke is pivoted at Q, to the lever I.

The operation will now be plain. The cam M gives the lateral or angular motion to the lever I, and the cam N gives it its vertical motion; but as these motions are being offected there is practically absolute smoothness in the working of the parts, since the two driving-cams have independent connections with the lever, one of which is pivotal; 5 hence there can be no tendency to bind and no undue friction.

My second feature of improvement has for its object to obviate certain undesirable features incident to the form of joint employed loo to pivotally support the horizontal lever which directly connects with the feed-bar. These joints are commonly of some form of universal joint, in which the bearings of the two axes are close together. This construction calls for very accurate, andhence costly, work, and in proportion to the closeness of these bearings is the liability of loose and poor adjustment; furthermore, the horizontal lever is often necessarily unduly enlarged to receive such a joint, and thus the space necessary for the swing of the shuttle-lever may be intruded upon.

In my construction, R indicates a boss or projection on the bed-plate, which serves as a support for the lever K, and is placed quite to one side of the range of the shuttle-lever. Through this boss (which is sectioned away to show it) runs the stem S of the fork T, pivoted to and supporting the lever K. The stem S has a long bearing in the boss, and thereby can be held very securely and against any act-i011 tending to raise it to lose its adjustment. The yoke T is light in construction, and the lever K is made slender. The advantages of this form of joint are cheapness in the production of it and the feed-lever, greater ease in mounting and adjusting the lever, and greater stability in the support of the feed-lever, and hence its smoother working.

I am aware that various forms of cams and yokes and forks have been used to connect the vertical feed-lever to the main shaft, as also that various forms of universal joints have been employed to support the horizontal feed-lever, and none of these do I claim; but

What I do claim is as follows:

1. In a sewing-machine, the combination, with the main shaft, the food-bar, the horizontal feed-bar lever mounted on a universal joint, and the vertical feed-bar lever, with the fulcrum through which it reciprocates, of two cams upon the main shaft, one engaging a fork on the vertical feed-bar lever and one engaging a yoke pivotally attached to said lever, substantially as and for the purpose set forth.

2. In a sewing-machine, the combination, with the main shaft, the feed-bar, the horizontal feed-bar lever mounted on a universal joint, and the vertical feed-bar lever supported upon and reciprocating through a vertically-adjustable fulcrum, of two cams upon the main shaft, a fork upon the vertical feed-lever engaging one of said cams, and a yoke engaging the other of said cams and pivoted to said lever, substantially as and for the purpose set forth.

3. In a sewing-machine, the combination, with the main shaft, of two cams thereon operating the fork of a vertical feed-lever and a link pivotally attached to said lever, and a fulcrum through which the lever reciprocates, with a feed-bar and a horizontal feed-bar lever K, supported in a fork T, having a pivotal stem S, substantially as and for the purpose set forth.

4. In combination, the feed-bar L and the feed-lever K and its pivotally-supportiu g fork S T, the vertical feed-lever having a vertically-adjustable fulcrum through which it reciprocaies, and the main shaft having two cams thereon, one engaged by a fork on the vertical feed-lever and the other inelosed by a link pivotally attached to said lever, sub stantially as and for the purpose set forth.

JAMES TRIPP.

Witnesses:

Ron'r. F. GAYLORD, FRANK B. MURPHY. 

